In times past, some trailers used "special shoot" footage, which is material that has been created specifically for advertising purposes and does not appear in the actual film. The most notable film to use this technique was Terminator 2: Judgment Day, whose trailer featured elaborate special effects scenes that were never intended to be in the film itself. "Special Shoot" trailers are the exception to the rule and usually do not occur very often, but when they are used the results have been remarkable. One of the most famous "special shoot" trailers is that used for the 1960s thriller Psycho, which featured director Alfred Hitchcock giving viewers a guided tour of the Bates Motel, eventually arriving at the infamous shower. At this point, the soft-spoken Hitchcock suddenly throws the shower curtain back to reveal Vera Miles with a blood-curdling scream. "Special Shoot" trailers have proven to be effective at creating a great sense of anticipation for movie goers and have been instrumental in generation elevated levels of revenue generation for the production studios.
The people who create trailers often begin their work while the movie is still being filmed. Since the edited movie does not exist at this point, the trailer editors work from snippets which are called rushes or dailies. The trailer may be created at the trailer editor agency while the movie itself is being cut together at the studio. Thus, the trailer may contain footage that is not in the final movie. It is also not uncommon for the trailer editor and the movie editor to use different takes of a particular shot. Another common trailer editing technique is to include music on the trailer which does not appear on the movie's soundtrack. This is nearly always a requirement, as trailers and teasers are created long before the composer has even been hired for the film score - sometimes as much as a year ahead of the movie's release date.
Motion picture trailers as well as print materials such as posters regularly become collectible items that are coveted by movie goers world-wide. A cottage industry has been created around associated items that are made available to the public during the time of the promotion and the pre-release of a major motion picture. Imagine the price of an original first run printing of the movie poster associated with a movie classic like "Gone With The Wind" or "The Wizard of Oz".